This relates to a vertical cavity surface emitting laser (VCSEL). A conventional VCSEL comprises a substrate having first and second major surfaces, a first distributed Bragg reflector (DBR) on the first major surface of the substrate, an active region on the first DBR, and a second DBR on the active region. The two DBRs form a laser cavity; and when an appropriate current is supplied to the VCSEL, laser emission takes place along the longitudinal axis of the VCSEL.